Issued  May  21, 1910. 

U.  S.  DEPARTMENT  OF  AGRICULTURE. 


FARMERS’  BULLETIN  403 


PREPARED  BY  THE  OFFICE  OF 
PUBLIC  ROADS. 


WASHINGTON: 

GOVERNMENT  PRINTING  OFFICE 

1910. 


LETTER  OF  TRANSMITTAL. 


U.  S.  Department  of  Agriculture, 

Office  of  Public  Roads, 
Washington ,  D.  O.,  February  25 ,  1910. 

Sir:  I  have  the  honor  to  transmit  herewith  a  manuscript  entitled 
“The  Construction  of  Concrete  Fence  Posts.”  The  fencing  in  of  the 
rights  of  way  may  properly  be  considered  a  road  problem.  The 
growing  scarcity  of  lumber  and  its  constant  increase  in  price  have 
made  it  necessary  to  turn  to  new  materials,  and  much  success  has 
followed  the  use  of  concrete  for  this  purpose.  I  recommend  that 
this  manuscript  be  published  as  a  Farmers’  Bulletin. 

Respectfully, 

L.  W.  Page,  Director. 


Hon.  James  Wilson, 

Secretary  of  Agriculture. 


403 


2 


CONTENTS. 


Comparative  advantages  of  concrete  and  wooden  fence  posts .  5 

Materials  for  making  concrete .  6 

Sand .  (5 

Gravel .  g 

Crushed  rock .  7 

Cement . 7 

Molds  for  line  posts .  g 

Steel  molds .  8 

Wooden  molds .  8 

Molds  for  square  posts .  9 

Molds  for  triangular  posts .  14 

Oiling  the  molds .  17 

Reenforcement .  17 

Principles  involved .  17 

Kinds  of  reenforcement .  18 

General  remarks .  20 

The  concrete .  21 

Appliances  used  in  mixing .  21 

Mixing  a  six-post  batch .  22 

Proportioning  the  ingredients .  23 

Mixing  ‘‘bank-run  ”  gravel .  24 

Mixing  crushed  rock  or  screened  gravel .  24 

Concrete  posts .  25 

Molding .  25 

Curing .  25 

Building  the  fence . 26 

Setting  the  posts .  26 

Methods  of  attaching  wire .  26 

Stretching  the  fencing .  28 

Line  anchors .  28 

Cost  of  concrete  posts .  28 

Miscellaneous  posts  which  may  be  made  of  concrete . 

Corner  posts .  29 

Bracing  posts  and  braces . 

Gate  posts  and  hitching  posts . 

Vineyard  and  arbor  posts . 

Warning .  ^1 

403 


3 


ILLUSTRATIONS. 


Page. 

Fig.  1.  Gang  mold  for  posts  without  taper .  10 

2.  Gang  mold  for  posts  tapering  on  two  sides .  12 

3.  Gang  mold  for  posts  tapering  on  all  sides .  13 

4.  Molds  for  triangular  posts .  15 

5.  Gang  mold  for  triangular  posts .  16 

6.  Showing  effect  of  reenforcement .  18 

7.  “  Fool-proof  spacer  ”  for  reenforcement .  20 

8.  Methods  of  attaching  fence  wire  to  concrete  posts .  27 

9.  Method  of  constructing  brackets  for  bracing  posts . .  30 

403 

4 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


Many  things  have  contributed  to  make  concrete  one  of  the  leading 
building  materials  of  the  day.  It  has  shown  its  worth  as  a  substitute 
for  wood  because  of  its  moderate  cost,  its  durability,  the  ease  with 
which  it  is  handled,  the  wide  distribution  of  sand,  gravel,  and  stone 
which  enter  into  its  composition,  and  the  tremendous  growth  of  the 
cement  industry.  It  has  been  thoroughly  tried  and  tested,  not  only 
in  laboratories,  but  also  by  years  of  actual  use  by  the  United  States 
Government,  by  state  agricultural  colleges,  by  railroads  and  stock 
yards,  and  by  hundreds  of  farmers,  and  it  has,  among  other  things, 
proved  successful  in  the  construction  of  fence  posts. 

COMPAEATIVE  ADVANTAGES  OF  CONCRETE  AND  WOODEN 

FENCE  POSTS. 

As  a  material  for  the  construction  of  fence  posts,  concrete  has  not 
only  very  few  of  the  disadvantages  and  practically  all  of  the  advan¬ 
tages  of  wooden  posts,  but  it  is  also  superior  to  timber  in  some 
respects.  In  the  first  cost  concrete  posts  may  be  more  or  less  expen¬ 
sive  than  the  best  wooden  posts,  according  to  the  locality.  This 
depends  upon  the  timber  supply,  the  deposits  of  gravel  and  rock,  and 
the  skill  exercised  by  the  person  making  the  concrete  posts. 

If  manufactured  as  usual  and  cured  for  three  months,  concrete 
posts  are  as  good  as  the  best  wooden  posts  of  the  same  size.  After 
three  years’  service  wooden  posts  possess  only  from  one-third  to  one- 
half  of  their  original  strength,  whereas  concrete  grows  stronger  with 
age  and  needs  no  repairs,  for  neither  weather  nor  fire  injures  it.  Un¬ 
der  ordinary  circumstances,  good  concrete  posts  will  last  forever; 
and  even  if  a  few,  in  the  course  of  years,  should  be  broken  by  unusual 
strains,  it  is  cheaper  to  replace  these  than  to  replace  an  entire  fence 
of  decayed  wooden  posts  with  posts  of  material  with  the  same  lack  of 
durability. 

V  _  -  «  • 

Concrete  posts  are  attractive  in  appearance  because  of  their  uni¬ 
formity  of  size  and  color  and,  because  of  their  durability,  they  eifect 
a  saving  in  giving  greater  life  to  the  fencing  material  used,  so  that 
the  permanent  value  of  the  property  is  increased. 


403 


6 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


MATERIALS  FOR  MAKING  CONCRETE. 

SAND. 

The  sand  to  be  used  in  making  concrete  must,  above  all  things,  be 
coarse  and  clean.  Coarse  sand,  varying  in  the  size  of  the  grains, 
is  generally  clean  and  dense,  and,  therefore,  produces  a  denser  and 
stronger  concrete  than  fine,  light  sand.  Drift  sand  makes  very  weak 
concrete,  while  dirty  sand  weakens  the  mortar  and  often  delays  its 
setting.  The  difficulties  encountered  in  making  concrete  are  often 
ascribed  to  the  cement,  but  more  frequently  they  are  due  to  the  poor 
quality  of  sand.  The  presence  of  dirt  in  the  sand  is  easily  ascer¬ 
tained  by  rubbing  a  little  in  the  palm  of  the  hand.  If  a  little  is 
emptied  in  a  pail  of  water,  the  presence  of  dirt  will  be  shown  by  the 
discoloration  of  the  water.  This  can  be  discovered  also  by  filling  a 
fruit  jar  to  the  depth  of  4  inches  with  sand  and  then  adding  water 
until  it  is  within  an  inch  of  the  top.  After  the  jar  has  been  well 
shaken,  the  contents  should  be  allowed  to  settle  for  a  couple  of  hours. 
The  sand  will  sink  to  the  bottom,  but  the  mud,  which  can  be  easily 
recognized  by  its  color,  will  form  a  distinct  layer  on  top  of  the  sand 
and  above  both  will  be  a  clear  depth  of  water.  If  the  layer  of  mud 
is  more  than  one-half  inch  in  thickness,  the  sand  should  not  be  used 
unless  it  is  first  washed.  Loam  and  clay  may  be  washed  out  either 
on  a  wooden  platform,  a  wire  screen,  or  in  an  inclined  V-shaped 
wooden  trough.  A  small  amount  of  clay  in  sand,  for  example,  5  per 
cent,  does  not  decrease  its  value  for  use  in  cement  mortar,  provided 
that  the  clay  is  not  in  lumps.  In  fact,  for  mixtures  lean  in  cement, 
the  clay  seems  to  add  density  and  strength.  Deposits  of  good  sand 
are  frequently  found  in  stream  beds. 

GRAVEL. 

Gravel,  just  as  dug  from  the  pit,  is  sometimes,  though  very  rarely, 
found  with  the  right  proportions  of  sand  and  pebbles.  The  mixture 
best  suited  for  concrete  is  two  parts  sand  to  four  parts  pebbles,  in 
which  all  sizes  less  than  one-fourth  of  an  inch  in  diameter  are  con¬ 
sidered  sand.  As  there  is  generally  too  much  sand  for  the  gravel, 
it  is  advisable  to  screen  the  sand  from  the  gravel  by  using  a  screen 
with  a  mesh  of  one-fourth  of  an  inch  and  then  to  remix  it  in  the  proper 
proportions.  All  pebbles  larger  than  1  inch  should  be  rejected. 
Gravel  should  contain  no  decayed  stone  and  should  be  clean,  in  order 
that  the  cement  may  adhere  to  it.  If  dirty,  it  can  be  washed  in  the 
same  way  as  sand.  Valuable  deposits  of  gravel  are  often  to  be  found 
in  stream  beds,  valleys,  and  at  the  foot  of  hills. 

403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS.  7 

CRUSHED  ROCK. 

The  best  crushed  stone  for  concrete  is  that  which  is  clean  and  hard 
which  breaks  with  a  sharp,  angular  fracture,  and  to  which  mortar 
easily  adheres.  Trap,  granite,  and  limestone  are  among  the  best, 
while  the  use  of  shale,  slate,  sandstones,  and  very  soft  limestones 
should  be  avoided.  The  largest  stones  allowable  in  the  manufacture 
of  posts  are  those  1  inch  in  diameter. 

Crushed  rock  should  be  screened  only  enough  to  remove  the  dust. 
The  small  particles  are  not  a  detriment,  but  a  decided  advantage, 
since  they  reduce  the  amount  of  cement  mortar  required  and  give  to 
the  concrete  additional  density  and  strength.  However,  in  propor¬ 
tioning,  small  particles  with  a  diameter  less  than  one-fourth  of  an 
inch  must  be  considered  as  sand. 

CEMENT. 

Kinds  of  cement. — There  are  two  general  kinds  of  cement  on  the 
market,  natural  (sometimes  called  Kosendale  or  hydraulic)  and  Port¬ 
land.  The  processes  of  manufacture  of  both  kinds  are  well  known, 
and  there  are  no  patents  to  restrain  anyone  from  engaging  in  their  pro¬ 
duction.  The  several  manufacturers  put  out  many  brands  of  each  kind 
with  special  names,  but  all  fall  in  these  two  classifications.  With 
varying  qualities,  the  principal  ingredients  of  both  cements  are  the 
same — silica,  alumina,  iron  oxide,  and  lime.  Natural  cement,  as  the 
name  implies,  is  a  product  direct  from  the  earth,  with  the  variations 
of  nature  in  the  proportions  of  its  ingredients.  It  is  burned  to  a  mod¬ 
erately  high  temperature,  and  from  the  resulting  clinker  the  finely 
powdered  cement  is  ground.  Portland  cement,  so  named  from  its 
resemblance  to  the  quarried  stone  of  Portland,  England,  is  a  carefully 
proportioned  mixture,  with  each  ingredient  measured  to  give  the  best 
results  when  combined  with  the  others.  The  whole  is  ground  to  a 
powder,  which  is  burned  to  a  clinker  at  a  very  high  temperature  and 
again  ground  to  the  fine  cement.  On  account  of  its  uniformity,  relia¬ 
bility,  quick  development  of  strength,  and  cheapness  of  cost,  Portland 
cement  has  practically  displaced  the  natural  article  on  the  market. 
Hereafter  all  reference  to  cement  will  mean  the  Portland  variety  only. 

The  scientific  tests  of  cement  are  too  complicated  and  too  expensive 
for  the  small  consumer.  In  selecting  a  cement  he  can  do  nothing 
better  than  to  choose  some  well-known  standard  brand,  guaranteed 
to  meet  the  standard  specifications  of  the  American  Society  of  Civil 
Engineers  and  the  American  Society  for  Testing  Materials. 

The  retail  price  of  cement  is  somewhat  dependent  upon  the  demand, 
the  freight  rates  from  the  factories,  and  the  quantity  purchased. 
Price  quotations  are  made  with  the  barrel  as  the  unit.  I  our  sacks  of 
95  pounds  each  make  a  barrel  of  Portland  cement. 

403 


8 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


Storage  of  cement. — Cement  must  be  kept  in  a  dry  place,  protected 
from  the  ground  and  out  of  danger  of  being  wet  by  driving  rains  and 
moisture-laden  drafts.  The  following  is  a  very  good  method  of  stor¬ 
ing  cement.  Upon  the  floor  should  be  placed  wooden  blocks  and 
over  these  a  loose  board  floor.  Upon  this  the  cement  is  piled  and 
then  covered  with  a  canvas  or  with  roofing  paper.  Cement,  once  wet, 
forms  lumps  and  is  entirely  unfit  for  use;  but  the  lumps  caused  by 
pressure  in  the  storehouse  must  not  be  mistaken  for  cement  that  has 
been  wet  and  has  then  formed  in  lumps.  Lumps  caused  by  pressure 
are  easily  broken  and  the  cement  is  perfectly  good. 

Water. — The  last  of  the  ingredients  forming  concrete  is  water,  and 
any  good-tasting  drinking  water  is  suitable  for  this  purpose. 

MOLDS  FOR  LINE  POSTS. 

Molds  for  concrete  line  posts  are  made  of  both  steel  and  wood,  and 
are  built  for  single  posts  or  in  “sets”  or  “gangs.”  In  deciding  the 
size  of  the  top  and  bottom  of  the  post,  and  consequently  of  the  mold, 
one  should  take  into  consideration  the  nature  of  the  ground  in  which 
the  post  will  be  set.  A  very  loose  soil  requires  a  post  with  larger  ends 
and  wider  sides  or  a  greater  length  for  deeper  setting  in  the  ground. 
A  careful  observation  of  the  smallest  wooden  post  found  satisfactory 
will  help  in  deciding  the  size  of  the  concrete  post. 

STEEL  MOLDS. 

The  purchaser  will  find  many  patented  steel  molds  on  the  market. 
It  is  advisable  to  buy  a  form  simple  in  its  general  shape,  for  in  such  a 
mold  the  reenforcing  can  be  placed  more  exactly  where  it  belongs. 
Steel  has  some  advantages  over  wood,  since  it  is  lighter,  less  cumber¬ 
some  to  handle,  and  gives  the  post  a  neater  finish  and  any  shape 
desired.  Where  the  appearance  is  important,  steel  molds  are  to  be 
preferred  to  wooden.  Neighbors  often  club  together,  when  this  is 
desirable,  in  order  to  buy  steel  molds  and  so  economize  in  this  expense. 

WOODEN  MOLDS. 

Wooden  molds  good  enough  for  ordinary  demands  are  very  easily 
made.  White  pine  is  the  best  wood  for  this  purpose,  but  at  the  same 
time  it  is  the  most  expensive.  Cheaper  kinds  of  lumber,  which  are 
easy  to  work  with,  may  be  used.  Molds  made  of  2-inch  planks, 
dressed  on  both  sides,  form  neater  posts,  but  lighter  lumber  may  be 
used,  if  the  forms  are  well  braced. 

In  imitation  of  the  manner  in  which  tree  trunks  grow,  concrete  posts 
are  usually  made  tapering  in  size  from  butt  to  top.  While  this  method 
may  add  a  little  to  the  appearance  of  the  post  and  effect  a  slight 
saving  in  concrete,  this  saving  is  largely  offset  by  the  additional  cost 

403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


9 


of  the  carpenter’s  work  and  of  the  lumber  used  in  making  the  molds. 
Theoretically,  the  tapering  post  has  a  better  design  than  the  one  with 
straight  sides,  but  for  ordinary  use  one  is  as  good  as  the  other. 

In  making  these  molds,  dressed  lumber,  planed  from  the  rough 
should  be  used.  The  proper  dimensions  for  rough  timber  are  1  or  2 
inches  thick  and  4,  6,  8,  10,  or  12  inches  wide;  for  dressed  lumber 
they  are  }  or  If  inches  thick  and  3f,  5f,  7},  9$,  or  11 J  inches  wide. 

MOLDS  FOR  SQUARE  POSTS. 

Molds  for  posts  that  are  square  or  nearly  square  in  cross  section 
are  simple  and  easy  to  make.  They  are  built  in  three  patterns:  (1) 
For  posts  without  taper;  (2)  for  posts  tapering  on  two  sides;  and  (3) 
for  posts  tapering  on  all  four  sides. 

In  order  to  avoid  a  sharp,  irregular  edge,  neater  posts  arc  made 
by  fastening  a  narrow  strip  of  canvas  or  leather  on  the  inside  of  the 
side  board  at  the  bottom  of  the  mold,  so  that  when  the  mold  is  put 
together  and  the  concrete  post  molded  the  corner  of  the  post  will 
be  rounded.  A  similar  effect  on  the  upper  side  of  the  post  is  produced 
by  using  a  trowel  or  an  “edger” — a  special  tool  for  rounding  the 
corners  of  concrete  walks  or  curbs.  Clay  plastered  in  the  corner 
of  the  mold  or  wooden  strips  tacked  to  the  sideboards  will  answer 
the  same  purpose.  Such  strips  must,  however,  be  as  small  as  pos¬ 
sible  or  else  they  will  crowd  out  much  concrete,  and  thus  cause  the 
reenforcement  to  be  located  too  far  within  the  post  to  obtain  the 
best  results.  Ordinarily  the  reenforcement  should  be  placed  within 
three-fourths  of  an  inch  or  1  inch  of  the  outside  of  the  post. 

For  posts  without  taper. — The  easiest  and  cheapest  mold  to  make 
is  the  straight  mold,  or  one  for  a  post  which  does  not  taper.  Such 
molds  are  merely  long  boxes  built  with  various  schemes  for  making 
the  molding  of  the  post  a  simple  matter.  On  account  of  the  amount 
of  lumber  saved  and  the  ease  with  which  these  molds  are  fflled, 
straight  molds  are  generally  made  in  “sets”  or  “gangs,”  by  con¬ 
structing  several  side  by  side  with  a  continuous  bottom  and  end 
pieces.  Figure  1  shows  the  plan  of  a  “gang”  mold  for  making  six 
posts,  each  of  which  is  7  feet  long  and  5  by  5  inches  at  both  ends. 
On  account  of  the  rigid  method  of  construction,  all  lumber  used  in 
this  mold,  with  the  exception  of  the  2  by  4  inch  stringers,  may  be 
1-inch  dressed  boards.  The  bottom  is  of  “ship  lap”  cut  to  the  di¬ 
mensions  indicated  on  the  drawing  and  nailed  tightly  to  the  three 
stringers.  The  end  pieces  (E)  are  made  up  of  one  board  each  to 
which  are  nailed  blocks  (B)  1  inch  in  thickness  and  5  inches  square, 
placed  so  as  to  allow  the  side  pieces  (S)  to  slip  between  them.  The 
end  pieces  are  hinged  to  the  bottom  with  strap  hinges  (II),  in  which 
the  fixed  pin  is  replaced  by  a  loose  pin  or  a  nail.  4  his  arrangement 
allows  the  end  piece  to  be  removed  at  will.  Shutter  hinges  or  loose- 
35710— Bull.  403—10 - 2 


10 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS 


403 


Fig.  1.— Gang  mold  for  posts  without  taper. 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


11 


pin  door  butts  of  heavy  wrought  iron  may  also  be  used  as  hinges.  All 
the  side  pieces  are  alike  and  interchangeable. 

The  form  is  set  up  ready  for  use  in  this  manner.  The  end  pieces 
are  placed  in  position  by  inserting  the  loose  pin  of  the  hinges.  Length¬ 
ened  wagon  rods  (W),  with  crank  nuts  (N)  at  one  end,  are  dropped 
into  the  slots  (K),  and  the  sideboards  are  then  placed  in  the  grooves 
(G)  between  the  blocks  on  the  end  pieces.  All  the  pieces  are  then 
drawn  together  by  tightening  the  crank  nuts  (N).  The  slots  for  these 
rods  should  be  faced  with  an  iron  strap  and  should  be  so  centered  that 
the  rods,  when  tightened,  will  lie  against  the  sides  of  the  outer  side 
pieces  and  act  as  stiffeners  for  them.  With  this  arrangement,  by 
merely  loosening  the  crank  nut  on  the  end  of  the  rods,  when  the  con¬ 
crete  has  sufficiently  set,  the  end  and  side  pieces  may  be  removed 
without  disturbing  the  posts  and  placed  on  a  similar  bottom  board, 
and  another  batch  of  posts  may  be  made.  The  first  batch  should  be 
left  on  the  bottom  board,  as  will  be  explained  later  on  pages  25  and  26. 

By  another  method  the  end  piece  is  hinged  to  the  bottom  like  the 
end  gate  of  a  spring  wagon  bed,  and  the  method  of  fastening  is  the 
same  as  generally  used  on  spring  wagons — spring  elbow  catches  fas¬ 
tened  with  screws  to  the  side  boards  and  flush  with  them — so  as  to 
allow  the  concrete  to  be  “ struck’ ’  when  the  molds  are  filled.  If  the 
molds  are  constructed  in  this  way,  the  outer  sideboards  should  be 
made  of  2-inch  lumber. 

For  posts  tapering  on  two  sides. — Posts  tapering  on  two  sides  are 
preferable  to  the  straight  posts  in  some  respects.  A  satisfactory 
size  for  this  style  is  produced  in  a  mold  4J  inches  deep  by  6  inches 
wide  at  the  butt,  4J  by  4J  inches  at  the  top,  and  7  feet  long.  These 
posts  may  be  made  more  easily  in  gang  molds,  which  are  built  so  as  to 
make  the  adjoining  posts  lie  butt  to  top.  By  considering  that  the  end 
positions  of  every  post  are  reversed,  it  is  possible  to  build  this  style  of 
mold  according  to  the  directions  set  forth  under  straight  molds.  (I  ig. 
2.)a  All  dimensions  for  this  mold  should  be  taken  carefully  from 
figure  1. 

For  posts  tapering  on  all  sides. — Square  posts  are  also  made  tapering 
on  all  sides.  A  line  post  of  a  satisfactory  size  may  be  obtained  by 
making  the  molds  5  inches  deep  by  6  inches  wide  at  the  butt,  3  inches 
deep  by  4  inches  wide  at  the  top,  and  7  feet  long.  Since  all  the  butts 
must  be  placed  at  one  end  and  all  the  tops  at  the  other,  this  arrange¬ 
ment  causes  the  continuous  bottom  in  figure  3  to  be  1  loot  "wider 
at  one  end  than  at  the  other.  The  variation  in  the  length  of  the  side¬ 
boards  and  of  the  molded  posts  is,  however,  so- slight  (liardl}  one- 
fourtli  of  an  inch  at  the  greatest)  that  no  attention  need  be  paid  to  it 

a  The  letters  indicating  the  various  parts  are  the  same  as  used  for  straight  molds  and 
in  the  paragraph  discussing  them. 

403 


12 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


403 


Fra.  2.— Gang  mold  for  posts  tapering  on  two  sides. 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS 


13 


403 


Fig.  3. — Gang  mold  for  posts  tapering  on  all  sides. 


14 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


and  all  sideboards  can  be  made  the  same  length.  The  construction 
of  the  mold  will  easily  be  understood  from  figure  3,  and  from  the 
description  of  the  end  pieces,  with  the  manner  of  hinging  and  fasten¬ 
ing  them  to  the  side  pieces,  as  given  under  straight  molds.  All  the 
dimensions  for  this  mold  must  be  taken  carefully  from  figure  3. 

MOLDS  FOR  TRIANGULAR  POSTS. 

Triangular  molds  without  a  taper  are  easily  constructed  in  “sets” 
or  “gangs.”  On  account  of  their  shape,  they  may  be  braced  at  any 
point  and,  as  a  result,  1-inch  boards  may  be  used  in  their  construction. 
In  figure  4,  molds  for  three  sizes  of  triangular  concrete  posts  are 
shown.  The  two  boards  are  hinged  together  at  the  ends  and  quarter 
points  on  the  bottom  by  ordinary  3-inch  wrought-iron  strap  hinges 
bent  to  conform  to  the  shape  of  the  mold  and  fastened  with  f-inch 
screws. 

Sharp  corners  on  the  finished  post  are  somewhat  objectionable, 
on  account  of  their  roughness  and  sharpness,  and  the  possible  waste 
of  material.  This  undesirable  feature  is  avoided  by  placing  a  wooden 
tongue  or  strip  (T)  in  the  bottom  of  the  form,  as  shown  in  figure  4, 
and  by  rounding  the  corners  at  the  upper  face  either  with  a  trowel  or 
an  edger  (see  p.  9). 

The  manner  of  supporting  and  bracing  the  gang  triangular  mold  is 
shown  in  figure  5.  Three  2  by  4  joists  (J)  should  be  cut  with  each 
4  feet  8f  inches  in  length.  Beginning  at  either  end,  3f  inches  should 
be  laid  off  for  the  cleated  lock  piece  (P)  made  of  a  2  by  4  inch  board 
with  cleats  of  strips  1  by  2  by  3 §  inches.  The  lock  piece  laid  under 
the  joists,  as  shown,  serves  to  bind  them  together.  Then  1^  inches 
should  be  marked  off  for  the  strip  (U)  on  the  end  board,  3  inches 
for  a  half  brace  block  (b),  and  afterwards  1  f-inch  openings  for  the 
insertion  of  the  hinged  sideboards  (S)  and  6  inches  for  the  full  brace 
blocks  (B),  until  six  posts  are  provided  for,  with  a  half  brace  block, 
strip,  etc.,  at  the  other  end.  The  brace  blocks  (B)  are  cut  from 
scantling  2  by  6  inches.  They  are  5J  inches  deep,  and  are  2  inches 
wide  at  the  top  and  6  inches  at  the  bottom,  where  they  are  nailed 
to  the  joist  (J). 

The  ends  (E)  for  the  molds  are  made  from  1  by  10  inch  boards 
and  are  4  feet  1|  inches  long.  They  are  fastened,  at  the  bottom 
side,  to  the  joists  (J)  by  means  of  heavy,  loose-pin  wrought-iron 
strap  hinges,  shutter  hinges,  or  door  butts  (H),  and  at  the  upper 
side  with  wagon  rods  (W)  and  wing  nuts  (N)  or  with  elbow  catches 
(see  also  fig.  3).  Until  all  of  the  molds  of  the  gang  are  partially 
filled  with  concrete,  it  is  sometimes  necessary  to  keep  them  from 
spreading  open  at  the  center  by  using  a  tie  brace  made  from  a  2- 
incli  board  with  blocks  of  1  inch  in  thickness  attached  so  as  to  fit 
the  molds  when  the  brace  is  in  place. 

403 


Fig.  4. — Molds  for  triangular  posts. 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


15 


403 


16 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


With  slight  changes,  similar  forms  may  be  built  for  medium  and 
light  posts.  Triangular  posts  tapering  on  all  sides  can  be  built, 


but  the  molds  are  difficult  to  construct,  and  the  amount  of  material 
saved  is  not  worth  the  trouble. 


403 


Fig.  5. — Gang  mold  for  triangular  posts. 


17 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 

OILING  THE  MOLDS. 

Concrete  lias  a  tendency  to  stick  to  either  steel  or  wood.  In 
order  to  yield  a  smooth  finish  to  the  post,  it  is  customary  to  give 
the  inside  of  the  molds  a  coating  of  oil.  Soft  soap  or  crude  oils 
used  sparingly  serve  the  purpose  well.  Too  much  oil  will  destroy 
the  setting  qualities  of  the  cement  and  will  give  a  face  roughened 
with  pockmarks.  A  small  amount  of  oil,  poured  into  a  pail  of 
water  and  applied  with  a  mop  or  stiff  broom  in  scrubbing  out  the 
molds  after  they  have  been  used  five  or  ten  times,  or  as  often  as 
necessary,  will  prevent  the  concrete  from  sticking. 

REEITFORCEMENT. 

PRINCIPLES  INVOLVED. 

Concrete  and  steel  render  valuable  assistance  to  each  other  in  the 
support  of  heavy  burdens.  On  a  solid  foundation,  loaded  from 
above  and  thus  under  direct  pressure,  a  concrete  column  will  with¬ 
stand  the  strain  of  an  enormous  load.  A  much  smaller  load  so 
placed  as  to  cause  stretching  or  bending  toward  one  side  of  the  same 
column  may  cause  it  to  snap  off,  for  concrete  is  strong,  but  brittle. 
On  the  other  hand,  steel  is  tough  and  elastic.  In  the  form  of  rods  or 
wire,  steel  withstands  massive  loads  that  tend  to  stretch  it,  and  thus 
displays  a  kind  of  strength  directly  opposite  to  that  of  the  plain  con¬ 
crete  column.  In  modern  construction  these  two  valuable  properties 
of  concrete  and  steel  are  utilized  by  combining  them  in  what  is 
called  reenforced  concrete.  With  steel  properly  buried  in  the  con¬ 
crete,  the  column  withstands  not  only  the  load  which  might  other¬ 
wise  snap  it,  but  one  many  times  larger  and  even  though  it  is  applied 
at  any  place  along  its  length. 

Reenforcement,  therefore,  is  steel  in  the  form  of  bars,  rods  or  wires, 
buried  in  concrete  to  take  up  and  to  withstand  the  strains  which 
tend  to  stretch  or  to  bend  the  concrete.  A  concrete  fence  post  is 
merely  a  small  concrete  column.  Reenforced,  it  easily  stands  the 
strain  from  usage  in  a  fence  line. 

The  value  of  reenforcing  concrete  posts  properly  may  readily  be  seen 
from  figure  6.  If  a  load  (L)  is  raised  so  that  its  weight  is  supported 
on  one  side  by  a  wooden  post,  the  post  will  bend,  as  in  figure  0. 
The  fiber  in  the  wood  on  the  side  away  from  the  load  may  be  tough 
and  elastic  enough  to  prevent  the  post  from  breaking,  and  when 
released  the  post  will  spring  back  into  its  former  position.  In  the 
third  figure  a  No.  9  wire  (W)  is  fastened  secfirely  to  the  wooden 
post  at  the  top  and  at  the  ground  surface,  and  is  supported  along  its 
length  by  the  struts  (S).  If  the  same  load  is  applied,  the  post  will 
not  bend,  because  the  wire  takes  up  the  bending  or  stretching  strain. 

403 


18 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


This  is  precisely  the  case  with  the  reenforcement  in  a  concrete  post. 
Supported  along  its  length  by  the  concrete,  the  wire  (W)  or  steel  in 
other  shapes  takes  up  the  bending  or  stretching  strains.  Since  the 
load  which  causes  bending  or  stretching  may  come  from  any  direction, 
concrete  posts  are  reenforced  on  every  side;  otherwise  they  might 
break  in  a  manner  somewhat  similar  to  that  in  which  the  wooden 
post  bends  when  the  reenforcement  is  not  on  the  proper  side  of  the 
post. 

In  the  effort  to  be  safe  it  is  a  common  fault  to  insert  more  reen- 
forcement  than  is  absolutely  necessary.  This  adds  needlessly  to  the 
cost  of  the  post,  for  concrete  posts  become  stronger  as  they  grow 
older. 

KINDS  OF  REENFORCEMENT. 


With  regard  to  the  roughness  of  the  outside,  metallic  reenforcing 
materials  are  divided  into  two  classes,  smooth  and  corrugated  or 


Fig.  6— Showing  effect  of  reenforcement. 


deformed.  The  general  result  of  the  many  tests  carried  on  in  testing 
laboratories  seems  to  indicate  that  in  strength  of  bond,  if  the  con¬ 
crete  is  sufficiently  rich  and  well  mixed,  smooth  surfaces  give  satisfac¬ 
tory  results.  Two  kinds  of  reenforcement  are  much  used — bars  and 
wire. 

Bars. — Round  bars  three-sixteenths  or  one-fourth  of  an  inch  in 
diameter  are  the  size  and  kind  most  used  in  posts.  The  stock  on 
hand  at  blacksmith  shops  and  hardware  stores  is  generally  from  steel 
that  stretches  too  easily  and  therefore  is  not  the  best  for  reenforce¬ 
ment.  Companies  which  make  a  specialty  of  reenforcing  materials 
can  furnish  both  rods  and  bars  which  stretch  only  under  very  large 
loads. 

Wire. — The  development  of  the  wire  fence  has  produced  a  material 
well  suited  for  reenforcing  purposes.  Of  equal  size,  such  wire  will 
produce  a  stronger  post  than  the  material  described  above.  Single 

403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


19 


No.  8  or  two  No.  12  wires  twisted  are  sufficiently  strong  as  reen¬ 
forcement  for  ordinary  line  posts.  In  order  to  obtain  straight  wire 
of  the  necessary  length,  the  coils  ordinarily  placed  on  the  market 
should  not  be  straightened  out.  Straight  wire  can  be  obtained 
from  dealers  in  the  same  manner  as  baling  wire;  that  is,  either  single 
or  twisted  into  two  or  three  ply  cables  and  of  the  length  desired. 
The  plain,  ungalvanized  fencing  wire  is  the  proper  kind,  for  galva¬ 
nization  adds  nothing  to  the  strength  and  the  metal  will  not  rust  when 
incased  in  the  concrete. 

The  following  table  will  be  convenient  in  determining  the  size  and 
weight  of  wire  desired  for  reenforcement  or  for  other  uses: 


Sizes  and  weights  of  wire. 


Gauge. 

Feet  to 
pound. 

Gauge. 

Feet  to 
pound. 

Gauge. 

Feet  to 
pound. 

Gauge. 

Feet  to 
pound. 

1 

4.68 

6 

10.17 

11 

25.82 

16 

95.98 

2 

5.44 

7 

11.97 

12 

33.69 

17 

128.6 

3 

6.31 

8 

14.29 

13 

44.78 

18 

166.2 

4 

7.38 

9 

17.05 

14 

58. 58 

19 

223 

5 

8.75 

10 

20. 57 

15 

72.32 

20 

309.6 

The  “fool-proof  spacer.” — In  order  that  the  reenforcement  may  be 
placed  and  kept  just  where  it  belongs,  there  is  in  use  a  little  device 
called  the  “ fool-proof  spacer.”  It  consists  of  a  No.  10  wire,  cut  to 
such  length  that,  when  twisted  once  around  each  of  the  two  reenforc¬ 
ing  wires  or  rods,  the  ends  will  nearly  touch  the  sides  of  the  mold 
(fig.  7).  The  distance  from  the  twist  to  the  end  of  the  short  wire  is 
equal  to  the  distance  from  the  reenforcement  to  the  side  of  the  mold. 
In  triangular  molds  such  a  spacer  can  be  used  only  on  the  two  rods 
or  wires  near  the  top  of  the  mold.  A  shorter  and  similar  device, 
with  only  one  twist,  may  be  used  on  the  lower  reenforcement.  At 
least  three  spacers  should  be  placed  on  each  piece  of  reenforcement. 

Spacers  on  No.  8  wire,  which  should  be  placed  three-fourths  of  an 
inch  from  the  inside  of  the  mold,  should  be  made  from  the  following 
lengths  of  wire  for  the  various  sizes  of  triangular  posts: 


Length  of  wire  for  spacer  (in  inches)  for  triangular  posts. 


Heavy- 

posts. 

Medium 

posts. 

Light 

posts. 

TTrmpr  snappr  . 

6£ 

61 

51 

Tiftwp.r  s'nap.p.r  . 

2 

2 

if 

403 


20 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


Spacers  on  No.  8  wire  for  various  sizes  of  square,  or  nearly  square, 
posts  should  be  made  from  the  following  lengths  of  wire: 


Length  of  ivire  for  spacer  ( in  inches)  for  square  posts. 


Straight 
posts — 

5  by  5. 

Posts  ta¬ 
pering  on 
two  sides — 
4J  by  6, 

4 b  by  4\. 

Posts  ta¬ 
pering  on 
four  sides — 
5  by  6, 

4  by  3. 

Bottom  spacer . 

51 

m 

6i 

5| 

4} 

Middle  spacer . 

bi 

6 

5} 

Top  spacer . 

5} 

Fig.  7.—“  Fool-proof  spacer"  for  reenforcement. 


For  larger  or  smaller  reenforcing  a  little  additional  length  may  be 
added  or  deducted.  When  the  proper  length  has  been  determined, 
a  number  of  spacers  should  be  prepared  and  slipped  on  the  reenforc¬ 
ing  iron  by  way  of  preparation  for  placing  it  in  the  mold.  This  serves 
to  hasten  the  work. 


GENERAL  REMARKS. 

Reenforcing  should  be  placed  near  the  outside  wall,  where  it  is 
reasonable  to  expect  that  cracks  will  open.  For  reenforcement,  metal 
slightly  rusted  is  as  good  as  metal  that  is  not  rusted,  if  not  better. 
In  placing  the  reenforcing  rods  in  position  it  is  a  wise  precaution  to 
bend  them  back  at  the  ends  (fig.  7).  This  takes  only  a  little  more 
time,  but,  if  it  is  done,  the  reenforcement  must  be  2  inches  longer  to 

403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


21 


allow  the  metal  to  be  turned  back  1  inch  at  each  end  of  the  post. 
New  barbed  wire  should  not  be  purchased  for  reenforcement  for* 
while  it  costs  more  than  plain  reenforcement,  the  bond  between  it 
and  the  concrete  is  no  stronger  than  between  smooth  wire  and  con¬ 
crete.  The  danger  section,  or  the  point  where  posts  are  liable  to 
break,  is  at  the  surface  of  the  ground.  For  fences  for  lots  and  other 
places  where  posts  may  be  subject  to  rubbing  and  crowding,  short 
extra  reenforcing  pieces  2  feet  long  are  sometimes  placed  in  the  post 
to  lap  this  danger  section.  The  corner  of  triangular-shaped  posts 
which  is  not  nearest  the  fence  wire  should,  in  theory,  have  heavier 
reenforcement  than  either  of  the  other  corners.  If  rods  three-six¬ 
teenths  of  an  inch  in  diameter,  No.  8  wire,  or  two  twisted  No.  12 
wires,  are  used  in  the  other  corners,  a  rod  one-fourth  of  an  inch  in 
diameter,  or  two  or  three  twisted  No.  12  wires,  should  be  placed  in 
the  threatened  corner. 

THE  CONCRETE. 

APPLIANCES  USED  IN  MIXING. 

The  mixing  board. — The  size  of  the  mixing  board  depends  on  the 
number  of  men  employed  in  this  work  and  on  the  amount  of  room 
available  for  placing  the  board  in  position.  Sometimes  a  tight  and 
even  floor  in  a  building  may  be  used.  The  steel  sheet  from  the  plat¬ 
form  of  an  old  self-binder  may  be  used  for  a  mixing  board,  but  the 
larger  the  board  the  more  convenient  it  is.  For  two  men  mixing,  the 
board  should  be  8  by  12  feet;  for  four  men,  14  by  14  feet.  The  first 
size  is  usually  large  enough  for  making  posts.  It  should  be  built  of 
matched  inch  boards,  free  from  knots,  drawn  tightly  together  and 
placed  the  short  way  of  the  platform,  so  that  the  mixers  may  shovel 
with  the  cracks  and  not  against  them.  The  framework  should  con¬ 
sist  of  four  scantlings  2  by  4  inches,  laid  the  long  way,  and  with  the 
two  outside  ones  of  sufficient  length  to  afford  handles  for  carrying. 
The  location  for  the  board  should  be  fixed  before  the  sand,  stone,  and 
gravel  are  unloaded.  A  level  spot  with  sufficient  open  space  con¬ 
venient  to  the  work  and,  if  possible,  near  the  water  supply  should  be 
chosen.  Much  hard  labor  can  be  saved  by  locating  the  mixing  board 
lower  than  the  water  tank  and  by  siphoning  the  water  through  a 
garden  hose  to  a  barrel  or  other  receptacle  at  the  mixing  board.  The 
board  should  be  raised  on  blocks  until  it  is  level,  so  that  under  the 
weight  of  concrete  it  will  not  sag  in  the  middle.  If  water  is  added 
gradually,  as  it  should  be,  there  will  be  little  liquid  grouting  to  run. 
It  is  best,  however,  to  nail  a  2  by  2  inch  strip  or  a  piece  ol  2  by  4  inch 

scantling  around  the  edges  of  the  board. 

Runways. — If,  in  wheeling  the  materials,  runways  arc  necessary, 

they  should  be  built  so  that  they  will  be  smooth  and  strong.  Sliou  c 

403 


22 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


the  runs  be  over  2  feet  above  the  ground,  20  inches  is  none  too  great 
for  their  width.  The  speed  of  the  work  depends  upon  the  rate  of 
moving  the  materials  and  concrete. 

Tools. — One  great  advantage  in  using  concrete  is  that  it  can  be 
made  with  the  investment  of  very  little  money  in  special  tools.  If 
the  few  required  are  not  already  at  hand  for  other  purposes,  the  new 
ones  will  serve  in  many  different  lines  after  the  concrete  is  finished. 
For  mixing,  it  is  necessary  to  have  from  two  to  four  square-pointed, 
short-handled  “paddy”  shovels,  size  No.  3.  A  couple  of  wheelbar¬ 
rows  with  steel  trays  and  with  a  capacity  of  2  cubic  feet  are  conven¬ 
ient  for  moving  the  sand,  stone,  and  concrete.  If  wooden  molds  are 
used,  a  metallic  sidewalk  “edger,”  with  a  curve  of  three-eighths  of 
an  inch  in  the  radius,  will  make  neat  corners.  A  comer  trowel,  or 
even  an  ordinary  trowel,  will  answer  the  same  purpose  fairly  well. 
Screens  may  be  made  by  nailing  J-inch  and  J-inch  mesh  wire  screen¬ 
ing,  2 1  by  5  feet,  to  frames  made  of  2  by  4  inch  lumber. 

The  measuring  box. — Since  construction  with  concrete  is  so  easy, 
many  persons  are  careless  about  the  exact  proportions  of  the  cement, 
sand,  and  gravel  or  crushed  rock  to  be  used  in  its  composition,  but 
this  is  a  very  important  point.  The  bottomless  box  with  handles 
attached  is  a  very  useful  article  for  this  purpose.  For  posts,  a  con¬ 
venient  measuring  unit  is  a  box  with  an  open  bottom  12  by  14f  and 
10  inches  deep,  measured  on  the  inside.  This  box,  filled  to  the  top 
with  the  loose  material  and  smoothed  level,  contains  practically  1 
cubic  foot.  The  inches  in  height  may  be  marked  with  brass  tacks. 
Then,  since  each  inch  in  height  represents  one-tentli  of  a  cubic  foot, 
the  measurements  are  easy.  If,  on  account  of  its  size,  the  use  of  this 
box  would  be  too  slow  for  measuring  the  sand  and  gravel,  larger 
boxes  or  wheelbarrows  may  be  gauged  and  used,  or  other  boxes  may 
be  made  on  the  same  principle.  It  is  a  very  poor  practice  to  count 
shovelfuls,  as  it  produces  unsatisfactory  and  even  dangerous  results. 

MIXING  A  SIX-POST  BATCH. 

The  following  table  gives  approximate  quantities  for  a  batch  of 
concrete  sufficiently  large  to  make  six  posts  7  feet  long  and  of  the 
sizes  named  in  the  table.  The  quantities  may  be  increased  in  like 
proportion  and  any  desired  number  of  posts  may  be  made.  The 
first  of  the  two  lines  of  figures  given  for  each  of  the  three  grades, 
heavy,  medium,  and  light,  indicates  the  proportions  to  be  used  when 
the  sand  is  screened  from  the  gravel.  The  second  line  gives  the  pro¬ 
portions  when  “bank-run”  gravel  is  used;  that  is,  gravel  dug  directly 
from  a  bank  without  screening  the  sand.  In  this  case  1  part  of 
cement  to  4  parts  of  the  mixture  of  sand  and  gravel  should  be  used. 

403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 

Quantities  of  material  and  resulting  amount  of  concrete  for  a  six-post  batch. 
TRIANGULAR  POSTS— LENGTH,  7  FEET. 


23 


Size  of  post. 


Heavy. . 
Medium 
Light. . . 


Proportions  of  materials  by 
parts,  measured  in  volume.' 


Cement. 


Sand. 


Gravel 
or  rock. 


Materials  in  cubic  feet, 
measured  loose. 


Cement. 


1.4 

1.5 

1.3 

1.4 
1.1 
1.2 


Sand. 


2.8 


2.6 

2.2 


Stone  or 
gravel. 


5.6 

6.0 

5.2 

5.6 

4.4 

4.8 


Concrete 

tamped, 

cubic 

feet. 


6.2 

6.2 

5.5 

5.5 

4.8 

4.8 


Water 

for 

mixing, 

gallons. 


11 

11 

10 

10 

9 

9 


RECTANGULAR  POSTS— LENGTH,  7  FEET. 


Straight,  5  by  5 . 

Taper  on  two  sides, 
4§  by  6,  4£  by  4§.... 
Full  taper,  5  by  6, 
4  by  3 . 


/  1 

2 

4 

1.7 

3.4 

6.8 

7.3 

\  1 

4 

1.8 

7.2 

7  3 

/  1 

2 

4 

1.6 

3.2 

6.4 

6.9 

\  1 

4 

1.7 

6.8 

6  9 

/  1 

2 

4 

1.5 

3.6 

6.0 

6.7 

\  1 

4 

1.6 

6.4 

6.7 

13 

13 

12 

12 

12 

12 


PROPORTIONING  THE  INGREDIENTS. 


On  account  of  the  variations  in  the  size  of  the  sand  grains  and  in 
the  unfilled  spaces  between  the  particles  of  sand,  stone,  and  gravel, 
the  quantities  of  concrete  made  according  to  the  proportions  above 
may  be  greater  or  less  than  those  stated  in  the  tables.  For  the  same 
reason  the  quantities  of  water  may  or  may  not  be  sufficient  to  make 
the  concrete  wet  enough.  Such  matters,  with  the  experience  gained 
through  making  a  few  batches,  may  be  easily  adjusted.  Water 
should  always  be  measured  by  the  bucket  to  have  uniform  results. 

Different  pockets  of  sand  and  gravel  and  different  “  crusher-run  ’  ’ 
rock  vary  in  size  and  consequently  hi  the  unfilled  spaces  or  voids 
between  the  grains  or  pieces.  This  variation,  in  theory,  calls  for 
varying  quantities  of  cement,  but  the  methods  of  determining  the 
exact  amount  of  these  unfilled  spaces  are  so  complicated  and  so  open 
to  mistakes  that,  with  cement  at  its  present  low  price,  it  is  cheapest 
in  the  long  run  to  adopt  proportions  or  mixtures  which  are  rich 
enough  to  guarantee  a  well-made,  strong  post.  If  unscreened  “  bank- 
run”  gravel  is  decided  upon,  it  should  be  used  in  the  proportion 
of  1  part  of  cement  to  4  parts  of  gravel.  For  crushed  rock  or 
screened  gravel  (which  is  much  better  than  “ bank-run”  gravel),  the 
concrete  should  be  used  in  the  proportion  of  1  part  of  cement,  2 
parts  of  sand,  and  4  parts  of  rock  or  gravel.  All  measurements 
should  be  made  with  the  material  poured  loosely,  into  the  measuring 
box,  and  the  box,  when  full,  should  be  leveled  smooth. 

The  amount  of  moisture  in  the  sand,  gravel,  and  stone  varies  so 
much  with  weather  conditions  that  the  quantity  of  water  for  a.  cubic 
foot  of  concrete  can  not  be  fixed  exactly.  During  the  mixing  ol 


403 


24  THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 

the  cement  with  the  sand  and  rock,  sufficient  water  should  be  used 
for  the  concrete  to  be  wet  enough,  when  the  mixing  is  complete,  to 
tremble  under  a  blow  from  the  shovel  and  to  run  into  the  molds. 
This  amount  of  water  causes  a  rich  mortar  to  flow  to  the  outside  of 
the  post  and  insures  a  smooth  finish.  A  force  pump  and  hose  afford 
a  convenient  means  of  conveying  water  to  the  work.  Often  by 
locating  the  mixing  board  lower  than  the  water  tank,  water  may  be 
siphoned  through  a  garden  hose  to  the  board. 

MIXING  “BANK-RUN”  GRAVEL. 

For  concrete  from  unscreened  “  bank-run  ”  gravel,  one-half  of  the 
amount  of  gravel  required  for  a  batch  of  posts  should  be  spread  out 
in  oblong  shape;  and  upon  this  should  be  evenly  distributed,  first 
the  full  amount  of  cement,  and  then  the  remainder  of  the  gravel. 
Two  men  facing  each  other  and  at  the  same  end  of  the  batch  (and, 
if  necessary,  two  at  the  other  end),  with  square-pointed  “ paddy ” 
shovels,  turn  the  dry  cement  and  gravel  with  a  “flopping,”  dragging 
stroke.  By  timing  their  strokes,  the  mixers  can  cause  their  shovels 
to  meet  regularly  at  the  middle,  which  insures  the  complete  mixing 
of  all  the  materials.  For  a  thoroughly  mixed  concrete,  no  definite 
number  of  turnings  can  be  fixed,  but  the  shoveling  should  be  con¬ 
tinued  until  the  cement  no  longer  shows  in  streaks  or  until  the  mix¬ 
ture  has  a  uniform  color.  Skillful  concrete  turners  do  not  lift  the 
shovel  from  the  board  and  “flop”  over  its  contents  as  though  they 
were  turning  “flapjacks,”  but  by  gradually  turning  the  shovel  and 
at  the  same  time  dragging  the  stroke,  they  completely  mix  the  dry 
cement  and  gravel  in  two  turnings.  When  the  scattered  materials 
around  the  edges  have  been  thrown  upon  the  pile,  it  is  cut  open  and, 
using  a  sprinkler — a  sprinkler  bucket  or  a  hose  with  spray  attach¬ 
ment — about  three-fourths  of  the  water  required  is  added.  Water 
dashed  from  buckets  or  from  the  ordinary  nozzle  of  a  hose  causes  a 
waste  of  cement.  The  mixture  is  again  turned  and  cut  open  as 
before.  Then  the  remaining  one-fourth  of  the  water  is  added  and 
the  mixture  is  turned  again.  With  careful  workmen,  the  concrete 
should  now  be  well  mixed ;  but,  if  it  shows  dry  spots,  it  must  be  turned 
once  more.  After  this  the  concrete  should  be  shoveled  into  a  com¬ 
pact  ridge,  ready  to  be  wheeled  away  to  the  molds  or  to  be  shoveled 
into  them.  The  mixing  board  should  be  thoroughly  cleaned  at  the 
close  of  each  day’s  work.  Persons  who  intend  to  make  the  manufac¬ 
ture  of  posts  a  business  will  do  well  to  invest  in  a  good  power  mixer. 

MIXING  CRUSHED  ROCK  OR  SCREENED  GRAVEL. 

In  general,  where  crushed  rock  or  screened  gravel  is  used,  the  mix¬ 
ing  is  very  similar  to  that  of  “bank-run”  gravel.  The  full  amount 
of  sand  is  spread  out  upon  the  board  and  upon  it  the  necessary 

403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


25 


cement  is  evenly  distributed.  The  whole  is  turned  dry  until  the 
cement  no  longer  shows  in  streaks  and  the  color  of  the  batch  is  uni¬ 
form.  The  mixture  is  then  spread  out  flat,  just  as  the  sand  was,  and 
upon  it  the  crushed  rock  or  screened  gravel  is  distributed  evenly. 
Three-fourths  of  the  required  water  is  added  and  the  mixing  is  con¬ 
tinued  as  for  mixing  “ bank-run”  gravel.  In  dry,  hot  weather  it  is 
a  good  plan  to  throw  water  on  the  pile  of  crushed  rock  before  mixing. 

CONCRETE  POSTS. 

MOLDING. 

After  the  molds,  which,  as  a  rule,  lie  flat,  have  been  oiled  or  soaped, 
the  concrete  should  be  placed  in  them  at  once.  If,  for  any  reason, 
the  concrete  stands  thirty  minutes  after  mixing,  it  should  be  thrown 
away  and  a  new  batch  mixed,  for  cement,  if  it  has  once  partially  set, 
makes  weak,  dangerous  concrete,  even  though  it  is  retempered  by 
turning  or  adding  water.  After  the  molds  are  filled  evenly  to  the 
depth  of  three-fourths  of  an  inch  or  1  inch,  according  to  the  spacing 
of  the  reenforcing  rods  or  wires,  the  reenforcement  should  be  laid  in, 
properly  spaced  by  means  of  at  least  three  “  fool-proof  ”  wire  spacers. 
The  concrete  should  then  be  poured  in  until  the  molds  are  filled 
within  three-fourths  of  an  inch  or  1  inch  of  the  top,  when  the  remaining 
reenforcement  is  fitted  in  place  in  the  manner  described  above  and 
the  molds  are  completely  filled.  To  render  the  concrete  more  com¬ 
pact,  a  crowbar  or  a  pinch  bar  should  be  placed  under  each  corner  of 
the  mold  successively  and  moved  up  and  down  quickly.  This  vibra¬ 
tion  makes  the  concrete  more  compact  by  shaking  out  the  air  bubbles, 
but  there  will  be  very  few  of  these  bubbles  if  the  concrete  is  suffi¬ 
ciently  mixed  to  proper  consistency.  If  desired,  the  exposed  corners  of 
the  post  may  be  beveled  with  an  “edger”  and  the  open  face  given  a 
neat  finish  by  using  a  trowel  immediately  after  the  surface  water 
has  been  absorbed  and  before  the  concrete  has  become  too  hard. 

If  wooden  molds  are  used,  they  should  be  well  soaked  in  water,  so 
that  the  green  concrete  will  not  cause  them  to  swell  and  thus  crack  the 
posts. 

The  wind,  the  hot  sunshine,  and  the  frost  are  destructive  to  con¬ 
crete;  and,  while  it  is  an  easy  matter  to  protect  the  post  from  the 
first  two  agents,  it  is  best  to  do  no  concrete  work  when  the  thermome¬ 
ter  is  below  the  freezing  point,  unless  inside  a  building. 

CURING. 

It  is  a  great  mistake  to  believe  that,  when  the  molding  is  done,  a 
concrete  post  is  finished.  The  quality  of  the  post  must  be  determined 
by  curing.  The  green  post  should  bo  left  in  the  mold  until  thoi 
oughly  hardened;  that  is,  usually  for  two  or  three  days.  1 01  squaie 

403 


26 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


or  nearly  square  posts  the  molds  proper  may  then  be  removed  and 
used  on  another  bottom  board,  but  the  posts  must  stay  on  their  bot¬ 
tom  board  in  the  shade  and  must  not  be  disturbed  for  at  least  a  week 
or  ten  days.  Posts  in  triangular  molds  may  be  carried  out,  each  in 
its  own  mold,  after  from  five  to  seven  days,  and  the  post  may  be 
gently  slid  from  its  mold  to  a  smooth  floor  covered  evenly  with  a 
cushion  of  sand.  While  green  the  strain  of  lifting,  or  even  a  slight 
jar,  will  cause  cracks,  sometimes  invisible,  which  greatly  weaken  the 
post.  During  the  first  two  days  of  the  life  of  a  post  it  must  be  kept 
wet  and  covered  with  canvas,  burlap,  carpet,  or  any  clean  material. 
Sand  will  serve  after  the  concrete  has  become  hard,  but  manure  will 
stain  green  concrete  and  otherwise  affect  it.  The  sprinkling  should  be 
continued  up  to  the  eighth  day.  After  the  tenth  day,  if  the  space  is 
needed,  the  post  may,  with  care,  be  placed  on  end  in  the  same  manner 
that  wooden  fence  rails  were  formerly  piled.  A  drop  of  only  6  inches 
often  breaks  a  green  post.  The  jar  in  hauling  to  the  field  over  rough, 
frozen  roads  or  in  a  wagon  bed  with  a  very  uneven  bottom  has  seriously 
injured  posts  which  were  not  well  seasoned.  Concrete  posts  gain 
rapidly  in  strength  for  the  period  of  one  year;  they  should,  therefoie, 
be  made  as  long  as  possible  before  it  is  necessary  to  set  them  in  the 
fence.  No  post  should  be  used  until  it  is  at  least  3  months  old, 
and,  to  meet  any  contingency,  a  supply  of  well-seasoned  posts  should 
be  kept  on  hand. 

BUILDING  THE  FENCE. 

SETTING  THE  POSTS. 

Experience  has  taught  that  with  regard  to  stringers  and  joists,  in 
order  to  get  the  greatest  strength  from  the  timber,  one  should  place 
the  beam  with  the  narrow  side  against  the  load  and  with  the  depth 
extending  in  the  same  direction  as  the  pressure.  Likewise,  posts 
should  be  placed  so  that  the  narrow  side  will  support  the  wire. 
This  will  give  the  greatest  resistance  to  breakage  from  animals  rubbing 
against  them  or  trying  to  get  through  the  fence  between  the  posts. 
The  depth  to  which  posts  should  be  set  varies  with  the  character  of 
the  soil.  Seven-foot  posts  are  usually  set  from  2\  feet  to  2  feet  8 
inches  deep.  The  earth  about  the  post  should  be  thoroughly  com¬ 
pacted  by  tamping. 

METHODS  OF  ATTACHING  WIRE. 

There  are  numerous  methods  of  attaching  wire  fencing  to  concrete 
posts.  Some  makers  place  staples  or  wire  loops  in  the  green  con¬ 
crete;  others  make  holes  in  the  posts.  The  former  method  is  not 
desirable  because  the  fastener  can  not  be  located  exactly  where  the 
wire  of  the  fencing  will  come  when  the  post  is  set  in  the  ground;  then, 
too,  the  fastener  will  eventually  rust  or  break  off  and  will  thus  injure 

403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


27 


the  looks  of  the  post.  On  the  other  hand,  holes  through  the  posts 
weaken  them  and  therefore  this  method  is,  in  general,  unsatisfactory. 

The  simplest,  easiest,  and  cheapest  way  of  fastening  a  wire  fence 
to  a  concrete  post  is  by  encircling  the  post  with  a  wire  one  size  less 
than  the  corresponding  wire  in  the  fence  proper  and  by  twisting 
this  wire  around  the  strand  of  the  fence.  This  is  done  in  two  ways. 
The  fastening  wire  is  placed  around  the  post,  twisted  upon  itself 
and  then  to  the  fence  wire;  or  one  end  of  the  fastening  wire  is  twisted 


Fig.  8.— Methods  of  attaching  fence  wire  to  concrete  posts. 


around  the  fence  wire,  and  the  free  end  is  then  carried  aiound  tie 
post  and  twisted  on  the  other  side  to  the  same  wire.  ^  (Fig-  ^  le 
latter  method  is  known  as  1  ‘  the  Western  Union  twist.  Either  p  an  is 
good,  but  care  must  be  taken  to  draw  the  fastening  wiie  tig  it,  or 
else  stock  trying  to  get  through  the  fence  may  raise  or  cius  i  cown 
the  fencing  with  their  heads.  If  any  trouble  is  experience.  ,  t  le  pos 
should  be  roughened  at  the  fastening  point  with  a  cold  c  use  . 

Expansion  and  contraction  of  the  fence  due  to  heat  and  cold  are 
cared  for  by  the  tension  curves  or  ‘  ‘  kinks  ’  ’  in  the  wo ven-wire  fencing, 

403 


28  THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 

and  no  fear  may  be  felt  in  drawing  the  fastening  wires  as  tight  as 
necessary.  Wooden  nailing  strips  should  never  be  embedded  in  the 
posts,  for  moisture  will  swell  the  wood  and  crack  the  concrete. 

STRETCHING  THE  FENCING. 

Good  tools  for  stretching  wire  fencing  may  be  found  in  almost 
any  fence  company’s  catalogue.  Stretchers  should  be  such  as  to 
be  easily  operated  by  one  man.  They  usually  consist  of  two  heavy 
chains,  one  of  which  is  fastened  to  a  post  at  the  corner  or  brace  in 
the  fence  and  the  other  by  means  of  a  large  hook  to  the  wooden 
clamp  which  holds  the  loose  fencing.  The  stretcher  proper,  oper¬ 
ated  by  a  lever,  is  the  connecting  link  between  the  chains.  By 
working  the  lever  back  and  forth,  dogs  reach  out,  grasp,  and  draw  in 
link  after  link  of  the  chain,  and  thus  tighten  the  fence.  The  best 
stretchers  are  also  automatic  in  releasing  the  wire.  Owing  to  the 
great  force  used  in  stretching  fencing,  it  is  advisable  from  the  stand¬ 
point  of  safety  to  purchase  stretchers  with  automatic  releases. 
There  are  many  good  automatic  single-wire  stretchers  on  the  market. 

LINE  ANCHORS. 

Concrete  posts,  by  their  weight,  serve  to  hold  fences  down  in  the 
gullies  of  hill  country.  Sometimes  in  such  places  and  occasionally 
under  other  conditions  the  wire  fencing  must  by  some  means  be 
staked  to  the  ground  to  prevent  small  animals  from  going  under  it. 
This  may  be  accomplished  either  by  digging  a  hole  under  the  fence, 
filling  it  with  concrete,  and  embedding  a  tie  wire  in  the  concrete,  or 
by  burying  a  block  of  concrete  around  which  the  tie  wire  has  been 
placed.  After  the  concrete  has  set,  the  fence  may  be  made  secure 
by  attaching  the  tie  wire  to  the  heavy  lower  wire  of  the  fencing. 

COST  OF  CONCRETE  POSTS. 

So  many  elements  enter  into  the  matter  of  cost  that  no  exact 
figure  can  be  given.  The  prices  of  labor,  molds,  cement,  sand,  stone, 
gravel,  reenforcement,  and  lumber  are  not  the  same  in  any  two  sec¬ 
tions  of  the  country.  The  cost  of  only  two  sizes  of  post  will  be 
considered  here — the  heavy,  triangular  and  the  straight,  square 
post,  each  of  which  has  a  standard  length  of  7  feet.  The  figures  are 
based  on  the  following  data:  A  mixture  of  1  part  of  cement,  2  parts 
of  sand,  and  4  parts  of  crushed  rock  or  screened  gravel;  a  reenforce¬ 
ment  consisting  of  two  No.  12  smooth  fencing  wires  twisted  into  a 
cable  and  cut  to  the  necessary  length  at  the  factory;  concrete  mixed 
by  hand;  all  materials  delivered  at  the  work,  and  all  labor  of  men 
and  teams  paid  for. 

With  the  heavy,  triangular  post,  if  considered  necessary,  a  slightly 
heavier  reenforcement  may  be  used  in  the  corner  of  the  post  away 
from  the  fence. 


403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 

Cost  of  materials  and  labor  and  of  the  finished  posts. 
HEAVY,  TRIANGULAR  POSTS. 


29 


Materials. 

Cost. 

Number 
of  posts. 

Cost  per 
post. 

1  yard  of  rock  or  gravel . 

$1.00 

1.00 

1.50 

a.02| 

.40 

.15 

29 

58 

18 

1 

}  5 

$0. 03* 
.01f 
.08* 
.04* 

.11 

1  yard  of  sand . 

1  barrel  (4  sacks)  of  cement . 

3  two-ply  No.  12  wire  cables  (weight,  If  pounds) . 

2  men  for  one  hour,  at  20  cents  per  hour . 

1  boy  for  one  hour,  at  15  cents  per  hour . 

Total  cost . 

.29 

STRAIGHT,  SQUARE  POSTS. 


1  yard  of  rock  or  gravel . 

$1.00 
1.00 
1.50 
a.  02i 
.40 
.15 

25 

50 

16 

1 

}  5 

$0. 04 
.02 
.09* 
.05 1 

.11 

1  yard  of  sand . 

1  barrel  (4  sacks)  of  cement . 

4  two-ply  No.  12  wire  cables  (weight  2\  pounds) . 

2  men  for  one  hour,  at  20  cents  per  hour . 

1  boy  for  one  hour,  at  15  cents  per  hour . 

Total  cost . 

.321 

a  Per  pound. 


Since  the  straight,  square  post  is  slightly  larger  than  the  heavy  ^ 
triangular,  it  costs  a  little  more. 

MISCELLANEOUS  POSTS  WHICH  MAY  BE  MADE  OF  CONCRETE. 

Concrete  posts  are  used  for  many  other  purposes  than  line  posts. 
The  sizes  are  slightly  different,  but  the  principles  and  general  lines  of 
design  are  the  same. 

CORNER  POSTS. 

Corner  posts  are  generally  made  with  square  ends,  8  by  8,  10  by  10, 
or  10  by  12  inches,  and  without  taper.  Heavier  reenforcement  is 
used  and  should  be  increased  in  amount  by  placing  extra  pieces  on 
all  four  sides  either  at  the  middle  or  one-third  points.  The  wire  may 
be  drawn  around  the  post  or  holes  may  be  made  through  it  by  placing 
greased  iron  rods  at  the  proper  places  in  the  green  concrete  and 
turning  them  about  occasionally  so  that  the  concrete  will  not  set  to 
them.  A  short  piece  of  pipe  may  be  placed  through  the  mold  and 
left  in  the  post  in  order  to  provide  a  hole.  Through  these  holes  the 
strands  of  wire  may  be  stretched  and  some  tightening  device  may 
then  be  used.  The  post  should  be  thoroughly  cured  belore  being 
strained  by  holding  a  tightly  stretched  fence. 

BRACING  POSTS  AND  BRACES.. 

Bracing  posts  should  be  placed  frequently  in  the  fence  line.  A 
mortise  for  inserting  a  brace  may  be  made  in  the  upper  end  b\  t<  nl~ 
porarily  placing  a  block  of  the  desired  dimensions  in  the  gieen 
This  operation  requires  considerable  skill  to  prevent  ruining  the  po.A. 

403 


30 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


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Some  persons  prefer  making  an  offset  or  bracket  (fig.  9)  on  the 
post.  Others  mold  the  post  and  brace  together  at  the  same  time. 

Braces  are  made  and  reenforced  like  line  posts.  The  ends  must  be 
molded  to  a  bevel  in  order  to  fit  the  offset  or  bracket  in  the  post. 

The  wire  brace  is  commonly  used, 
but  sudden  strains  are  liable  to 
crack  the  top  of  the  line  post  to 
which  the  wire  is  fastened.  An¬ 
other  brace  between  the  first  and 
second  line  posts  and  slanting  in 
the  same  direction  as  the  concrete 
brace  will  remove  such  danger.  A 
mass  of  concrete  run  around  the 
ground  end  of  the  brace  will  fix  it 
securely. 

GATE  POSTS  AND  HITCHING  POSTS. 

Gate  posts  are  made  in  the  same 
manner  as  corner  posts.  Hanging 
is  accomplished  by  using  a  hinge 
with  a  clamp  strap  which  entirely 
encircles  the  post.  Fasteners  are 
attached  in  the  same  way.  Holes 
for  bolt  hinges  are  sometimes  made 
in  the  post  during  the  molding. 
Large  iron  washers  should  then  be 
placed  between  the  post  and  the 
nut.  If  a  hole  is  desired  for  a  fast¬ 
ener,  the  hole  should  first  be  made 
by  inserting  a  piece  of  gas  pipe  in 
the  green  concrete. 

Hitching  posts  are  merely  line 
posts.  Wrought-iron  clamp  straps 
make  better  attachments  for  hold¬ 
ing  the  rings  than  holes  through  the 
post,  which  weaken  it. 

VINEYARD  AND  ARBOR  POSTS. 


Fig.  9. — Method  of  constructing  brackets 
for  bracing  posts. 


As  plenty  of  gravel  is  usually 
found  in  sections  where  grapes  are 
grown,  concrete  posts  are  very  convenient  in  the  culture  of  grapes. 
A  light  line  post  will  serve  the  purpose.  If  wire  or  an  iron  piece  is 
not  used  to  support  the  vines,  an  offset  or  bracket  should  be  made  on 
the  post  to  hold  the  cross  arm.  The  cross  arm  may  also  be  made  of 

403 


THE  CONSTRUCTION  OF  CONCRETE  FENCE  POSTS. 


31 


concrete.  Some  growers  prefer  to  erect  a  light  line  fence,  using 
smooth  wire  from  post  to  post  as  a  means  of  supporting  the  vines. 

Arbor  posts  are  constructed  in  the  same  manner  as  vineyard  posts. 
The  skeleton  work  may  also  be  made  of  concrete. 

WARNING. 

Persons  intending  to  buy  post  molds,  either  steel  or  wooden,  are 
warned  to  beware  of  unknown  traveling  agents  who  are  selling  molds, 
or  farm,  township,  and  county  rights  for  the  sale  or  use  of  their  respec¬ 
tive  molds.  Molds  should  not  be  purchased  from  strangers,  unless  one 
is  fully  satisfied  through  his  bankers  or  attorneys  that  the  company 
represented  by  the  agent  is  reliable  and  that  the  agent  is  their  true 
and  authorized  representative.  Often  such  persons  fraudulently 
claim  that  the  farmer  has  infringed  upon  their  patent  rights  by  using 
some  feature  of  their  article,  and  point  to  some  similarity  in  the  two 
articles  as  proof  of  their  statement.  After  a  discussion,  filled  with 
threats  of  suits  for  great  damages,  the  stranger  may  finally  agree,  on 
account  of  the  owner’s  ignorance  of  the  infringement,  to  release  him 
from  prosecution  for  a  sum  of  money  much  less  than  the  damages 
which  he  claims  he  could  obtain  in  court.  No  such  alleged  damages 
should  be  paid,  even  if  there  is  a  resemblance  between  the  two  articles. 
The  matter  and  the  agent  should  be  referred  to  one’s  lawyers.  This 
will  almost  always  settle  the  matter. 

As  for  township,  county,  and  state  rights  for  the  sale  of  articles, 
it  can  be  depended  upon  that,  if  this  were  such  an  easy  and  quick 
way  of  getting  rich,  the  agents,  despite  their  statements  of  lack  of 
time  to  work  the  field  and  the  necessity  of  personal  acquaintance, 
would  not  dispose  of  the  opportunity  to  anybody.  Above  all  things, 
no  papers  should  be  signed,  and,  while  cash  may  be  paid  for  the 
article,  it  should  be  paid  only  after  the  article  is  delivered.  A  num¬ 
ber  of  patents  have  been  granted  on  special  types  of  reenforced  con¬ 
crete  fence  posts.  These  special  types  of  reenforcement  can  not,  of 
course,  be  generally  used  without  danger  of  infringing  patent  rights. 
It  is  doubtful,  however,  if  any  of  these  special  forms  of  reenforcement 
present  any  great  advantages  over  the  simple  forms  of  reenforce- 
ment  described  in  this  bulletin.  As  far  as  simple  reenforced  concrete 
is  concerned,  it  should  be  remembered  that  it  has  been  in  common 
usage  in  all  countries  for  a  great  many  years,  and  can  not  be  covered 
by  patent  rights.  No  one  need  hesitate  to  use  this  form  of  construc¬ 
tion,  for  all  claims  that  the  general  use  of  reenforced  concrete  fence 
posts  is  controlled  by  patent  rights  are  unjustified  and  untrue. 


' 


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